Elderly Patients Present Unique Imaging Challenges

April 01, 2014

Radiologists are facing unique challenges in imaging the growing population of elderly patients.

As life expectancy continues to increase globally, radiologists are faced with unique challenges when imaging geriatric patients. In fact, studies have shown it may be 10 times more difficult to obtain useful clinical imaging information in elderly patients than in younger ones.

In 2009, more than 700 million people in the world were age 60 and older—triple that of the 1950 population, according to a 2010 United Nations (UN) Department of Economic and Social Affairs report. The segment of people aged 60 and older has increased from 8 percent in 1950 to 11 percent in 2009, and the UN estimates that proportion will increase to 22 percent by 2050.

“With the increasing age of the population, the elder generation has become the predominant figure in our society,” said Giuseppe Guglielmi, M.D., professor of radiology at the University of Foggia and the scientific institute Casa Sollievo della Sofferenza in San Giovanni Rotondo, Italy, who co-edited and contributed to the 2013 book, “Geriatric Imaging.”

“This has resulted in a significant increase in demand for health services which, along with the development of new effective therapeutic protocols dedicated to geriatric patients, as well as non-invasive techniques and increasingly accurate diagnostic methods,” Dr. Guglielmi said.

Because the elderly have a tendency to present with non-specific symptoms, radiologists are challenged to discern the boundary between normal findings of aging and pathological changes, said Dr. Guglielmi, who served as an RSNA William R. Eyler Editorial Fellow in 2003.

“To avoid overdiagnosis and overtreatment, it is important not to confuse the healthy elderly patient who complains of some ‘pain’ with the elderly patient who really needs medical intervention,” he added. “This, unfortunately, still happens very frequently. Therefore it’s necessary to know the ‘normality specification’ of the elderly; that is, what is the ‘norm,’ taking into account the para-physiological changes typical of older patients.”

Radiologists must also pay particular attention when administering contrast media in the elderly to prevent contrast-induced nephrotoxicity (CIN). Although some studies have shown a protective effect against CIN using N-acetylcysteine, which is an antidote for acetaminophen poisoning, results are not yet definitive. “It is a low cost, potentially cyto-protective drug that is easy to administer and with few side effects,” Dr. Guglielmi said. “It would seem an ideal product, but we have yet to determine whether it is really effective.”

Another consideration is that geriatric patients sometimes have to be maintained in uncomfortable positions for significant lengths of time during their imaging studies. However, Dr. Guglielmi said, significant progress in all areas of diagnostic imaging helps assuage this concern.

Volumetric spiral CT in the study of cardiovascular disease and CT virtual endoscopy are examples of such improvements, while MR imaging has opened new perspectives in the study of the central nervous system, particularly in the identification of cerebrovascular disease. Also, MR spectroscopy results have significantly improved the identification of early stage prostate tumors.

CT Speed Critical in Chest Imaging the Elderly

The latest generation of CT scanners help address issues particular to imaging the chest, said Manuela Mereu, M.D., a radiologist in the Department of Neuroscience and Imaging at SS Annunziata Hospital in Chieti, Italy. Because elderly patients are unable to hold their breath for long periods, speed in administering CT scans is essential to avoid motion artifacts.

“In this scenario, chest imaging in these patients should be based on fast technical strategies such as chest radiography and CT that allow imagers to obtain information with few or no changes in positioning,” said Dr. Mereu, who presented “Chest Imaging in the Elderly: What Every Radiologist Should Know About,” at RSNA 2013.

Other considerations for chest imaging in elderly patients include frailty, immobility and the presence of comorbidities such as previous surgery, hypertension, renal insufficiency and poor peripheral venous access. Moreover, numerous anatomical and physiological changes occur during the aging process involving the chest wall, mediastinum and lung parenchyma.

An elderly patient’s heart and aorta are characterized by several major involutions, including lengthening and dilation of the aorta—factors responsible for enlargement of the mediastinal contour in chest radiograph frontal projection. “Aortic atheromatic calcification is frequent but not always related to the gravity of the clinical situation,” Dr. Mereu said.

In the lungs, physiologic aging of the lung parenchyma characterized by macroscopic, microscopic and vascular modifications translates into the “elderly lung.” One manifestation is “barrel chest,” a result of ribcage deformity with an increased bilateral hyperlucency and homogeneous reduction of vascularization often associated with bronchial wall thickening and air bubbles. The changes are marked by a reticular pattern on CT scans with a thickening of interlobular and intralobular septa, cysts, bronchial dilatation and bronchial wall thickening.

“In this context, the correlation of the extent of fibrotic changes with clinical history and other pulmonary and extrapulmonary findings is crucial to differentiate these moderate basal fibrosis related to the aging process with those of interstitial lung disease, such as usual interstitial pneumonia and non-specific interstitial pneumonia,” Dr. Mereu said.

She cautions radiologists to be aware of the numerous changes in the chest that occur in the aging process and to implement a rigorous method for evaluating all of the subcomponents. By doing this, radiologists can more readily identify the signs of the onset of disease.

“Chest imaging findings should be always associated with the clinical context and previous examinations; whenever necessary a follow-up exam must be requested,” Dr. Mereu said.

Guglielmi

Mereu

Radiologists are facing unique challenges in imaging the rapidly growing population of elderly patients. Above: The latest generation of CT scanners helps address issues particular to imaging of the chest cavity.

Chest imaging in elderly patients presents special considerations for radiologists. Above: Frontal (a) and lateral chest X-ray (b) of a 78-year-old man show a “barrel chest” deformity with increase in the antero-posterior diameter (white arrows in b) with an apparent increase in lung transparency and hyperelevation of the right hemidiaphragm. Subsequent CT scans show atrophy of pectoral muscles (white arrows in c) partially responsible for the hyperluncency of lung parenchyma. Signs of pulmonary emphysema are not on CT (d). Hyperelevation of the right hemidiaphragm is due to muscle dyskinesia. Image courtesy of Manuela Mereu, M.D.